Zenbook UX305CA Touchscreen Stops Working

We recently got a Zenbook UX305CA for my wife, with one problem: the touchscreen simply stops working. I can make sure that Windows 10 is completely updated, all programs installed, everything works, and create a system restore point. Wife works with computer for a while, then shuts it down. The next day, the Zenbook starts back up, only no touchscreen capability. In fact, the system no longer even *recognizes* there is a touch screen. No Pen/Tablet icon in Control Panel. No listing in Device Manager. It's all gone. So I laboriously go through a System Restore, back to the last restore point, and upon restart the touchscreen works again. This does not appear to be tied to a particular Windows 10 update, but *something* is causing the system to stop recognizing the touchscreen. Having to create restore points and restore the system every single day is not an acceptable long term solution. By the way, it's not a hardware issue: this is the *second* identical Zenbook we bought from Fry's: the first one was replaced due to the exact same problem. At the time, I thought it was a hardware issue, but I no longer think so. Any ideas on how to troubleshoot this?